Paranoia2/utils/p2rad/raytracer.h
2020-08-31 19:50:41 +03:00

147 lines
4.0 KiB
C++

/***
*
* Copyright (c) 1996-2002, Valve LLC. All rights reserved.
*
* This product contains software technology licensed from Id
* Software, Inc. ("Id Technology"). Id Technology (c) 1996 Id Software, Inc.
* All Rights Reserved.
*
****/
#ifdef HLRAD_RAYTRACE
#ifndef RAYTRACER_H
#define RAYTRACER_H
#include <assert.h>
#include "cmdlib.h"
#include "mathlib.h"
#include <utlarray.h>
struct tface_t;
struct trace_t;
#define KDNODE_STATE_XSPLIT 0 // this node is an x split
#define KDNODE_STATE_YSPLIT 1 // this node is a ysplit
#define KDNODE_STATE_ZSPLIT 2 // this node is a zsplit
#define KDNODE_STATE_LEAF 3 // this node is a leaf
#define NEVER_SPLIT 0 // set to 1 to test tree efficiency
#define MAILBOX_HASH_SIZE 256
#define MAX_TREE_DEPTH 21
#define MAX_NODE_STACK_LEN (40 * MAX_TREE_DEPTH)
#define COST_OF_TRAVERSAL 75 // approximate #operations
#define COST_OF_INTERSECTION 167 // approximate #operations
struct KDNode
{
// this is the cache intensive data structure. "Tricks" are used to fit it into 8 bytes:
//
// A) the right child is always stored after the left child, which means we only need one pointer
// B) The type of node (KDNODE_xx) is stored in the lower 2 bits of the pointer.
// C) for leaf nodes, we store the number of triangles in the leaf in the same place as the floating
// point splitting parameter is stored in a non-leaf node
int m_iChild; // child idx, or'ed with flags above
float m_flSplitValue; // for non-leaf nodes, the nodes on the
// "high" side of the splitting plane
// are on the right
inline KDNode()
{
m_flSplitValue = 0.0f;
m_iChild = 0;
}
inline int NodeType( void ) const
{
return m_iChild & 3;
}
inline int TriangleIndexStart( void ) const
{
assert( NodeType() == KDNODE_STATE_LEAF );
return m_iChild >> 2;
}
inline int LeftChild( void ) const
{
assert( NodeType() != KDNODE_STATE_LEAF );
return m_iChild >> 2;
}
inline int RightChild( void ) const
{
return LeftChild() + 1;
}
inline int NumberOfTrianglesInLeaf( void ) const
{
assert( NodeType() == KDNODE_STATE_LEAF );
return *((int32 *)&m_flSplitValue);
}
inline void SetNumberOfTrianglesInLeafNode( int n )
{
*((int32 *)&m_flSplitValue) = n;
}
};
struct NodeToVisit
{
KDNode const *node;
vec_t p1f;
vec_t p2f;
};
class CWorldRayTrace
{
private:
vec3_t m_AbsMins;
vec3_t m_AbsMaxs;
float m_flBackFrac; // to prevent light leaks
tmesh_t *mesh; // pointer to mesh
CUtlArray<KDNode> m_KDTree; //< the packed kdtree. root is 0
CUtlBlockVector<tface_t*> m_TriangleList; //< the packed triangles
CUtlArray<int> m_TriangleIndexList;//< the list of triangle indices.
public:
CWorldRayTrace()
{
m_KDTree.Purge();
m_TriangleList.Purge();
m_TriangleIndexList.Purge();
ClearBounds( m_AbsMins, m_AbsMaxs );
m_flBackFrac = 0.0f;
mesh = NULL;
}
// make pointers to model triangles
void AddTriangle( tface_t *tf );
void SetBackFraction( float back ) { m_flBackFrac = back * 100.0f; }
// SetupAccelerationStructure to prepare for tracing
void BuildTree( tmesh_t *src );
void TraceRay( const vec3_t start, const vec3_t stop, trace_t *trace );
private:
// lowest level intersection routine - fire 4 rays through the scene. all 4 rays must pass the
// Check() function, and t extents must be initialized. skipid can be set to exclude a
// particular id (such as the origin surface). This function finds the closest intersection.
void TraceRay( vec_t p1f, vec_t p2f, const vec3_t start, const vec3_t direction, trace_t *trace );
bool TraceTexture( const tface_t *face, float u, float v, float w );
int MakeLeafNode( int first_tri, int last_tri );
float CalculateCostsOfSplit( int plane, int *list, int ntris, vec3_t min, vec3_t max, float &value, int &nleft, int &nright, int &nboth );
void RefineNode( int node_number, int *list, int ntris, vec3_t absmin, vec3_t absmax, int depth );
void CalculateTriangleListBounds( const int *tris, int ntris, vec3_t minout, vec3_t maxout );
float BoxSurfaceArea( const vec3_t boxmin, const vec3_t boxmax );
};
#endif//RAYTRACER_H
#endif//HLRAD_RAYTRACE